Dishwashing apparatus



July 5, 1960 A. B. MARMO ET AL DISHWASHING APPARATUS Filed Aug. 27.

United States Patent DISHWASHING APPARATUS Filed Aug. 27, 1957, Ser. No.680,461 '6 Claims. c1. 1s4-'174 This, invention relates to dishwashingapparatus and more particularly to front-opening dishwashing machinesofthe type employing a rotating body for distributing washing water. -Itis an object of this invention to provide improved apparatus of thiskind.

llomestic dishwashing machines. of the front-opening type. usuallycomprise a cabinet having a washing vat and an access opening to the vatformed in a front wall of thecabinet. Upper and lower roll-out racks forholding dishes in place and. means for projecting and distributingwashing water toward the dishes are ordinarily provided. On certaindishwashers where the water distributor is of the type that projectswater. upwardly, from a levelbelow the lowerdishrack, improperdistribution of washing water to the dishes on the upper rack results,so -that auxiliary sprays have been proposed to correct situation.Accordingly, the washing water is distributed to the upper and lowerregions of the vat from vertically spaced distribution points, centrallylocated adjacent each, dish storage region. Preferably, the spraysarezrotatable for better wash distribution, so that there istheadditional problem of providing a satisfactory means for rotating thewater distributor for which this invention .provides a solution.

W here- 1'oll-out dish racks are employed, arevolving water distributormay be pivotally mounted on the lower rack for movement in andout of thevat therewith, and

some means fordelivering a jet of'water to the distribui is ,providedawaterwdistributor, mounted for rotation on theilower dish rackv in .a"central region thereof, fordis tributing washing water to the upper andlower regions of the vat from respective upper and lower radial discharge portss This distributor revolves in response to impulses from acontinuous jet of washing water delivered to; an axial entrance openingformed in the bottom thereof. Theldistributor is positioned in spacedrelationship with a diverting nozzle for receiving water jetting acrossan air gap from the nozzle. Generally helical passages are formedin thenozzle so that the water forced therefrom possesses some angularmomentum for imparting rotational impulses to the distributor.

Accordingly, it is a further object of this invention toqrotatea washingwater distributor by means of impulses derived from a jet of waterpassed through the distributor and discharged through radial dischargeports.

:The foregoing and other objects are elfected by the invention aswill beapparent from the following description'and claims taken in connectionwith the accompanying drawings, forming a part of thisapplication,3inwhich: I

Fig. -1 'is-avertical, sectional view of a dishwashing machine ofthe-firont-opening type having a water distributor constructed andarranged in accordance with the inventienlaactshcw in e ev ti n;

Fig. 2 is an exploded view of the diverting nozzle havin'g'portionsbroken away, the converging tube, and a shell half of the waterdistributor shown in Fig. 1; and Fig. 3 is a vertical sectionalview ofthe assembled parts of Fig. 2 arranged in operating position.

Reference will'now be had to Fig. 1 of the drawings disclosing theinvention applied to a domestic dishwasher of the front-opening type,which includes a box-like cabinet 11. A vat structure 12 is disposedwithin an upper portion of the cabinet and has a bottom wall 13 whichslopes downwardlyand inwardly to define. a sump 14 for washing water.The bottom wall 13 also partitions the vat'from an apparatus compartment15 which houses a Washing water return and pumping system in the lowerportion of the cabinet.

A conventional access opening to the vat is formed in afront wall of thecabinet 11, and closed by a suitable door. The latter is movable to anopen horizontal position'below the opening for gaining access to thevat, all of whichis well understood. The opening and the door are notillustrated or described for the sake of brevity and since they form nopart of the present invention.

Upper and lower, wheeled, open-Work, dish storage racksf16 and 17,respectively, are supported for movement intoand out of the vat throughthe access opening by pairs of horizontal tracks 18. The latter extendfrom front to back within the vat and may be secured to the lateralwalls thereof in any suitable manner. The arrangement of the dish racks16 and 17 is such that a user can roll the racks outwardly through theaccess opening for convenienbloading and unloading of dishes, all ofwhich iswell known. i

Dishwashers of the class set forth are usually provided with controlledequipment for heating and admitting fresh water to the1vat 12 anddischarging vitiated water therefrom, "but .Tsince suchequipment formsno part of the" present invention, descriptions, and illustrations thereregion ofthe vat bottom wall 13 and its outer wall surfaceis. securedinIsealing relationship to the edge of theope'ning,.as by welding.

Attached to the end of the conduit 21 is a diverting nozzle .22, as bestshown in Fig. 2, having cylindrical walls and a plurality .of generallyhelical passages, all formed about a vertical axis. A plurality ofwarped vanes 39 define the helical passages for swirling the water as itpasses through the nozzle 22. Preferably, the nozzle 22-is molded fromplastic material suitablefor use at temperatures up to 250 R, such as aplastic commercially available under the name of -Durez. The nozzle 22also includes a circular flange 23 which extends horizontally from theupper end of the nozzle 22 and serves as a backsplash bafile.Energization of the motor 20 causes rotation of the pump 19, wherebyWashthe vanes 39 augments the initial swirl so that water leaving thenozzlelz'possesses considerable angular vek locity,; as well as upwardvelocity, for rotating a water distributor 24. I

A Water distributor? t the new? ha t wz ii n 3 ings is employed forreceiving and redirecting water forced from the nozzle 22 toward thedishes stored on the upper and lower racks 16 and 17, and to utilize aportion of the energy from the jet, for rotating the distributor m.

The distributor has side walls generallyjformed about a,

vertical rotational axis for defining a hollow, bullet-shaped shell 25with the domed portion uppermost and an axial opening formed coaxiallywith the nozzle 24 in a cylindrical base portion 26 for admitting ajetof water to the shell. The distributor 24 is supported in a centralregion of the vat 12 by portions of the lower rack 17, hereinafterdescribed. Further, the distributor 24 is movable with the lower rack 17so that, whenfthe rack 17 is in washing position, the distributor ispositioned for rotation about the vertical axis of the nozzle 22. i

In order that the shell 25 may be easily and economically molded andassembled, it is made in two similar, mating and complementary halves27, one of which is illustrated in Fig. 2. Preferably, the shell 25 ismade of material similar to that used for molding the nozzle. 22. Theshell halves 27 are adapted to be joined together along an inverted,generally U-shaped line lying in a vertical plane. A radially extendingflange 28 is formed at the mating edge of each shell. half 27 andincludes rabbeted portions for improving the joint. The flange 28extends outwardly from the shell wall and terminates above thecylindrical base portion 26. The distributor 24 is provided with severalradial discharge. passages 31 by forming a number of shallow, transversechannels 29 in the flange 28 of each shell half 27. The location of thechannels 29 is such that each channel 29 registers with a complementary.channel 29 of the other shell half 27 upon assembly of the distributor24. With this arrangement, streams of washing water are directedoutwardly through the radial passages 31 toward the upper and lower dishracks 16 and 17 from respective upper and lower portions of thedistributor 24. It is to be understood that the disclosed constructionincludes discharge passages 31 having substantial radial length, ratherthan slits in a thin wall, for the purpose of providing surfaces whichcan receive rotational forces from the discharging water. H

An open-end bearing 32 is formed in the upper portion .of the shellflanges 28 for receiving. a stationary journal to be describedhereinafter. The assembled distributor 24 is held together at theflanges 28 by screw fasteners or other suitable fastening means. 7

A circular opening is formed in a central region of the lower dish rack17. Annular portions 33 of the rack 17 adjacent the opening provideloosely fitting. means for supporting the distributor 24 in a centralregion of the vat when the distributor is stationary and for guiding thebase portion 26 and limiting transverse movement thereof during rotationof the distributor. Included in the lower rack 17 are several rod-likemembers which form a protective cage 34 about the distributor 24 andfurther support a downwardly extending stationary pin 35 which isjournalled to the bearing 32 of the distributor. The pin 35 and itssupporting cage 34 provide a thrustresisting, pivotal support for thedistributor 24 during its operation.

As best seen in Fig. 2, a generally frusto-conical tube 36 is arrangedsubstantially within the base portion 26 of the distributor, andarranged so that Washing water delivered from the nozzle 22 passesthrough the converging passages of the tube 36. An annular lip andgroove, generally indicated at 38, are formed respectively in the shellbase portion 26 and the tube 36 for positioning and securing the tube36. The purpose of the tube 36 is to funnel washing water from thenozzle 22 toward the interior of the shell 25, and, further, to minimizedownward return flow from Within the shell which may be occasioned whenthe water strikes internal portions of the Water entering the base ofthe distributor 24 possesses considerable rotational inertia as a resultof passing through the nozzle 22 and swirls upwardly into thedistributor 24 causing it to rotate in order to align the radialdischarge passages 31 with the swirling water. Once the distributor 24is up to speed, very little rotational energy of the swirling water islost to the distributor, and the distributor rotation virtually locksinto the rotation of the water. A rotational speed of approximately r.p.m.is well suited for the design of distributor shown.

Movement of the lower rack 17 to a washing position disposes the axialentrance opening of the distributor 24 in spaced relationship with thenozzle 22 and in position to receive rotational impulses impartedthereto by water jetting from the nozzle. Thus, efiective washing actionof dishes on both upper and lower racks is accomplished by means of aunique water distributor, rotatably mounted on the lower rack 17 for:unrestricted movement therewith into and out of the washing vat 12.

From the foregoing, it may be seen that an improved water distributingdevice has been disclosed which.utilizes impulse principles foreffecting rotation thereof. It is to be understood that, although thearrangement illustrated shows but two dish racks, the inventive ideaextends to apparatus for washing dishes stored on several dish racksarranged one above the other.

While the invention has been shown in but one. form,

it will be obvious to those skilled in the art that it is not solimited, but is susceptible of various changes and modifications withoutdepartingrf'rom the spirit thereof.

What is claimed is:

1. In a dishwashing machine, the combination of a cabinet having awashingchamber formed therein and a bottom wall defining a sump at thebottom ofthe chamber, movable upper and lower dish storage racks withinsaid chamber, a washing fluid distributor centrally located within saidchamber and including a base portion, said distributor comprising ahollow elongated shell having internally smooth side walls formedgenerally.

about a vertical axis, said distributor having radially extendingdischarge passages formed in the side walls for directing washing fluidto the upper and lower racks, means for supporting said distributor onone of said racks for free rotation about said axis, said base portionhaving an axial opening formed therein, means for delivering a jet ofwashing. fluid into said opening including a pump, said pump having aninlet connected to the sump and an outlet conduit extending through thebottom Wall into said chamber and terminating adjacent the lower rack,and a nozzle having generally helical passages formed therein, saidnozzle being stationarily supported at the end of said conduit fordirecting a jet of washing fluid from said conduit toward said opening,the construction and arrangement being such that said distributor iscapable of being rotated solely by the force of said fluid jet.

2. In a dishwashing machine, the combination of a cabinet having awashing chamber formed therein and a bottom wall defining a sump at thebottom of the chamber, movable upper and lower dish storage racks withinsaid chamber, a Washing fluid distributor centrally located within saidchamber and including a base portion, said distributor comprising ahollow elongated shell having internally smooth side walls formedgenerally about a vertical axis, said distributor having radiallyextending discharge passages formed in the side walls for directingWashing fluid to the upper and lower racks, means supporting saiddistributor on one of said racks for free rotation about said axis, saidbase portion having an axial opening formed therein, means fordelivering a jet of washing fluid into said opening including a pump,

said pump having an inlet connected to the sumpand an outlet conduitextending through the bottomwall into said chamber and terminatingadjacent the lower rack, and a nozzle having generally helical passagesformed therein about said axis, said nozzle being stationarily supportedat the end of 'said conduit for directing a jet of washing fluid fromsaid conduit toward said opening in paths non-radial to the axis andoblique with respect to a plane normal to said axis, the constructionand arrangement being such that said distributor is capable of beingrotated solely by the force on. said fluid jet.

3. In a dishwashing machine, the combination of a cabinet having a vatstructure and an apparatus compartment contained therein, upper andlower dish racks disposed within the vat structure, means for supportingsaid racks tor movement relative to the vat structure, a sump formed inthe bottom of the vat structure, a pump disposed in said apparatuscompartment for forcing washing fluid into said vat structure, said pumphaving an inlet connected to said sump and an outlet conduit extendingvertically upward into said vat structure through a bottom centralportion thereot, a diverting nozzle having generally helical passagestermed about a first vertical .axis, secured to the end of said conduitfor directing a jet of washing fluid from said conduit upwardly in pathsnon-radial to said first axis and oblique with respect to a plane normal.to said first axis, a washing fluid distributor vertically spaced fromsaid nozzle and comprising a hollow shell having side walls formed abouta second vertical axis, means supporting said distributor for rotationabout said second axis, said supporting means being secured to saidlower rack and arranged so that said second axis is substantiallyaligned with said first axis when the lower rack is in washing position,said shell having an axial opening formed in its base portion toradmitting fluid thereto from the nozzle and a plurality of radialdischarge passages formed in its side walls for directing washing fluidtoward the upper and lower racks respectively.

4. In a dishwashing machine, the combination of a cabinet having a vatstructure and an apparatus compartment contained therein, upper andlower dish racks disposed within the vat structure, means for supportingsaid racks for movement relative to the vat structure, a sump formed inthe bottom of the vat structure, a pump disposed in said apparatuscompartment for forcing washing fluid into said vat structure, said pumphaving an inlet connected to said sump and an outlet conduit extendingvertically upward into said vat structure through a bottom centralportion thereof, a diverting nozzle having generally helical passagesformed about a first vertical secured to the end of said conduit fordirecting a jet of washing fluid from said conduit upwardly in pathsnon-radial to said first axis and oblique with respect to a plane normalto said first axis, a washing fluid distributor vertically spaced fromsaid nozzle and comprising a hollow shell having side walls formedgenerally about a second vertical axis, and a substantially cylindricalbase portion, means supporting said distributor tor rotation about saidsecond axis, said supporting means being secured to said lower rack andarranged so that said second axis is substantially coaxial with saidfirst axis when the lower rack is in washing position, said shell havingan axial opening formed in the base portion thereof -for receiving fluiddischarged from said nozzle, said base portion having a tube disposedwithin a lower portion of the shell and extending convergingly upward 6y from said base portion, said shell having radial discharge passagesformed in its side walls tor directing washing fluid toward the upperand lower racks respectively.

5. In a dishwashing machine, the combination of a cabinet having a vatstructure and a bottom wall defining a sump at the bottom of said vatstructure, a dish rack movably supported within the vat structure, awashing fluid distributor comprising a hollow shell having internallysmooth side walls formed about a vertical axis, means supporting saiddistributor on said rack for free rotation about said axis, saiddistributor having an axial opening formed in one end thereof foradmitting fluid thereto and a plurality of radially extending passagesformed in its side walls for directing washing fluid toward said rack,means including a pump for delivering washing fluid to said distributor,said pump having an inlet connected to said sump and an outlet conduitthrough which washing fluid is conducted, a stationarily supporteddiverting nozzle disposed in spaced relation to said distributor andadapted to direct washing fluid from said outlet conduit into saidopening in the distributor, said nozzle having generally helicalpassages formed about an axis which is aligned with said distributoropening, whereby washing fluid is directed toward said distributoropening in paths non-radial to the axis of said distributor and obliquewith respect to a plane normal to the axis of the distributor.

6. In a dishwashing machine, the combination of a cabinet having a vatstructure, said vat structure having a sump formed in the bottomthereof, said cabinet having an access opening to said vat structureformed in a front wall thereof, a dish rack disposed within the vatstructure, means for supporting said rack for movement between a washingposition within said vat structure and a loading position at leastpartially outside said vat structure, a washing fluid distributorcomprising a hollow shell having internally smooth side walls formedabout a vertical axis, means supporting said distributor on said rackfor free rotation about said axis, said distributor having an axialopening formed in the base portion thereof for admitting washing fluidthereto and having at least one radially extending discharge passageformed in its side walls for directing washing fluid toward said rack, anozzle stationarily supported within said vat structure in spacedrelation to said distributor for directing a jet of washing fluidupwardly into said opening in the distributor when said rack is in itswashing position, said nozzle having generally helical passages formedtherein for causing said jet of washing fluid to enter said distributorin paths nonradial to the axis of said distributor and oblique with respect to a plane normal to said axis, and means including a pump forforcibly conveying washing fluid from said sump through said nozzle.

References Cited in the file of this patent UNITED STATES PATENTS-695,967 Thurman Mar. 25, 1902 1,345,412 Smith July 6, 1920 2,664,903Sway Jan. 5, 1954 2,734,520 Abresch Feb. 14, 1956 2,751,917 Low June 26,1956 2,808,063 Abresch Oct. 1, 1957

